Water powered pumps have been employed in sumps in basements of residences and commercial buildings to prevent flooding of basements and the damage caused by such flooding. Sump pumps powered by pressurized water can eliminate requirements for electricity to sense water level and to power a motor that drives a pump. The complete elimination of electricity for sump pump operation is desirable because weather conditions which cause a rise in sump water level are likely also to cause electrical power failures.
Water powered pumps such as the pump shown in U.S. Pat. No. 5,302,088, the disclosure of which is incorporated herein by reference, work very well for discharging water from a sump. However, pump control systems that include a valve that is opened and closed by a float do not always work well. Corrosion and mineral deposits on valve components that occur over time, increase the force required to open and close a valve. The force available from a float usable in a confined sump is limited. Corrosion and deposits on a float over time and leakage of water into floats can also change the force a float can produce. The increase in the force required to open or close a control valve and changes in the force available from a float can lead to a situation in which the float is incapable of either opening or closing a valve that controls the supply of water under pressure to a water powered pump. A sump pump which is not turned on when water level in a sump rises to a high level, or is not turned off when the water level in a sump falls below a chosen low level is unsatisfactory.
Inspections and frequent maintenance can ensure the proper operation of a water powered sump pump. Unfortunately sump pumps are necessarily located in a sump where access for inspection and maintenance is difficult.